DIY Network

Engine Power Boost From "Classic Rides" episode DCLR-112

Figure A

In the last segment, host Kevin Tetz and Greg West, a Vespa restoration expert, installed a new, larger carburetor on the '74 Vespa Sprint Veloce project scooter. In this segment a cylinder kit will be installed to continue increasing the power of the scooter, and then the new wheels will be assembled.

Installing the Cylinder Kit

Note: Kevin and Greg are installing a DR 177 Cylinder Kit. The kit is going to balance out the extra air flow that comes with the new carburetor -- and it's going to make a nice match set -- and they won't have to get into the bottom end for these upgrades.

• To gain access to the assembly, start by removing the plastic cylinder cover (figure A), which directs the flow across the cylinder for the cooling.

• To gain access to the cylinder and piston, use a socket wrench to remove the three bolts that are attached to the head.

advertisement

	Figure B
	Figure C
	Figure D
	Figure E
	Figure F

• Slide the head off the piston and work it off the rings (figure B).

  Note: If there's carbon buildup on top of the piston, you'll want to clean it off.

• Use snap-ring pliers to remove the cir clips, the wrist pin and then remove the piston.

  Note: The cir clips are responsible for holding the wrist pin in the middle of the piston.

• Using an extension and a hammer, tap out the wrist pin from the cylinder cage to free up the piston.

• Remove the old top-end bearing.

• To finish the removal, slip the cylinder gasket off (figure C).

• Now it's time to install the new piston (figure D -- new one on right). To begin the installation, lube the new bearing and place it back into the rod.

• Next, slide the cylinder gasket onto the assembly.

• To install the new piston, start by lubing the new wrist pin, which helps keep the piston secure.

  Tip: When installing a new piston, make sure the arrow always points toward your exhaust port on the cylinder.

• Line up the piston and feed the lubed wrist pin through the opening.

• Using pliers, grip the new cir clips that came with the cylinder kit and insert them into each end. The clips hold the wrist pin in place.

• Make sure the ring gaps (figure E) at the locator pin, which keeps the ring from shifting inside the cylinder and getting over in front of the ports again. To install the ring, spread it out and push the ring onto the lip, rocking so it slides onto the piston. Repeat the same process for the second ring.

• Lube the inside of the cylinder and the piston.

• Wiggle the cylinder base down the studs, compressing the locator rings and slide the cylinder into place.

• Next, install the cylinder head with the spark plug hole facing the top.

• Install the lock washers and the nuts. Use a crisscross pattern to tighten the studs down snug with a socket wrench. Torque the head bolts (figure F) a little bit at a time, and finish them off at 156" torque pounds.

  Note: With the new cylinder kit installed on the project scooter, there will be substantial increase in power -- going from 150cc to 177cc.

Installing the New Wheel

• Tip the scooter engine and install the new wheel onto the hub.

  
  

• Next, install the lock washers and nuts to the rim of the scooter.

  
  

• Tighten down the lug nuts in a star pattern so the wheel will stay in balance and will not distort the rim.

  
  

• Tilt the engine back and slide the cover over the cylinder head and attach the bolt.

In the final segment of this next-to-last episode, Kevin and Greg start to reassemble the Vespa project scooter.

RESOURCES :

Eazyrizer Big Blue Motorcycle Lift (Driven Gear)
Driven Gear Inc.
Website: www.drivengear.com

RaceDeck Modular Flooring (SnapLock Industries)
SnapLock Industries
Website: www.racedeck.com

Vespa Restoration Parts (Scomo)
Scomo
Website: www.scomo.net

Air Compressor (Bend-Pak)
Bend-Pak, Inc.
Website: www.bendpak.com

Stock Photos, Videos, CD Rom and Timesurfer (Piaggio)
Piaggio, USA, Inc.
Website: www.piaggio.com/

GUESTS :

Greg West
Scooter Restoration Expert
E-mail: wheelsX2@yahoo.com